*,:before,:after{box-sizing:border-box}*{margin:0;padding:0}:root{--primary:#603bdf;--primary-dark:#4f2dcc;--primary-light:#ede8ff;--bg:#e9ebf2;--surface:#e9ebf2;--surface2:#e9ebf2;--text:#1a1523;--text-muted:#6b6680;--border:#d3d6df;--code-bg:#1e1e2e;--radius:18px;--shadow-raised:7px 7px 16px #c8cad1, -7px -7px 16px #fff;--shadow-raised-small:4px 4px 9px #c8cad1, -4px -4px 9px #fff;--shadow-inset:inset 4px 4px 9px #c8cad1, inset -4px -4px 9px #fff;--shadow:var(--shadow-raised)}body{background:var(--bg);color:var(--text);font-family:Segoe UI,system-ui,-apple-system,sans-serif;line-height:1.6}button,input,select,textarea{font:inherit}button:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible{outline:3px solid var(--primary);outline-offset:3px}::-webkit-scrollbar{width:6px;height:6px}::-webkit-scrollbar-track{background:var(--bg)}::-webkit-scrollbar-thumb{background:#c5c8d1;border-radius:3px}.module{max-width:1600px}.module-header{margin-bottom:40px}.module-badge{background:var(--bg);color:var(--primary-dark);text-transform:uppercase;letter-spacing:.08em;box-shadow:var(--shadow-raised-small);border-radius:20px;margin-bottom:12px;padding:5px 12px;font-size:11px;font-weight:700;display:inline-block}.module-title{margin-bottom:12px;font-size:34px;font-weight:800;line-height:1.15}.module-intro{color:var(--text-muted);max-width:65ch;font-size:16px;line-height:1.75}.section{margin-bottom:48px}.section-title{margin-bottom:10px;font-size:21px;font-weight:700}.section-text{color:#2d2840;max-width:68ch;margin-bottom:10px;font-size:15px;line-height:1.85}.callout{background:var(--bg);border-radius:0 var(--radius) var(--radius) 0;max-width:68ch;box-shadow:var(--shadow-inset);border-left:0;margin:16px 0;padding:16px 20px;font-size:14px;line-height:1.7}.callout strong{color:var(--primary-dark)}.confidence-list{flex-direction:column;gap:18px;max-width:68ch;margin-top:20px;display:flex}.confidence-row{background:var(--surface);border-radius:var(--radius);box-shadow:var(--shadow-raised-small);padding:16px 20px}.playground{background:var(--surface);border-radius:var(--radius);box-shadow:var(--shadow);border:0;margin:24px 0;overflow:hidden}.playground-header{color:var(--text-muted);text-transform:uppercase;letter-spacing:.06em;background:var(--surface);box-shadow:var(--shadow-inset);border-bottom:0;align-items:center;gap:8px;padding:10px 18px;font-size:12px;font-weight:700;display:flex}.playground-dot{background:var(--primary);opacity:.7;border-radius:50%;width:8px;height:8px}.playground-body{grid-template-columns:280px 1fr;display:grid}.playground-controls{background:var(--surface);border-right:0;flex-direction:column;gap:16px;padding:18px;display:flex;overflow-y:auto}.playground-preview{background-color:var(--bg);min-height:260px;box-shadow:var(--shadow-inset);background-image:radial-gradient(circle,#c8cad1 1px,#0000 1px);background-size:22px 22px;justify-content:center;align-items:center;padding:32px 24px;display:flex;overflow:auto}.playground-code{border-top:0;grid-column:1/-1}.ctrl-group{flex-direction:column;gap:6px;display:flex}.ctrl-label{color:var(--text-muted);text-transform:uppercase;letter-spacing:.06em;justify-content:space-between;font-size:11px;font-weight:700;display:flex}.ctrl-value{color:var(--primary);font-family:Cascadia Code,Fira Code,monospace;font-size:12px;font-weight:700}.ctrl-slider{width:100%;accent-color:var(--primary);cursor:pointer;height:4px}.ctrl-select{background:var(--bg);width:100%;color:var(--text);cursor:pointer;box-shadow:var(--shadow-inset);border:0;border-radius:10px;padding:8px 10px;font-family:Cascadia Code,Fira Code,monospace;font-size:13px}.ctrl-select:focus{outline:3px solid var(--primary);outline-offset:2px}.ctrl-toggle-row{flex-wrap:wrap;gap:4px;display:flex}.ctrl-toggle-btn{background:var(--bg);cursor:pointer;color:var(--text);white-space:nowrap;box-shadow:var(--shadow-raised-small);border:0;border-radius:9px;padding:6px 11px;font-family:Cascadia Code,Fira Code,monospace;font-size:12px;transition:color .15s,box-shadow .15s,transform .15s}.ctrl-toggle-btn:hover{color:var(--primary-dark);transform:translateY(-1px)}.ctrl-toggle-btn:active,.ctrl-toggle-btn.active{background:var(--bg);color:var(--primary-dark);box-shadow:var(--shadow-inset)}.ctrl-divider{background:var(--border);border:none;height:1px;margin:2px 0}@media (prefers-reduced-motion:reduce){*,:before,:after{scroll-behavior:auto!important;transition-duration:.01ms!important;animation-duration:.01ms!important;animation-iteration-count:1!important}}.app{flex-direction:column;min-height:100vh;display:flex}.app-header{z-index:200;background:var(--bg);position:sticky;top:0;box-shadow:0 5px 14px #a7aab557}.header-inner{justify-content:center;align-items:center;width:100%;padding:12px 24px;display:flex}.logo{color:inherit;flex-shrink:0;align-items:center;gap:12px;text-decoration:none;display:flex}.course-mark{width:64px;height:64px;box-shadow:var(--shadow-raised-small);border-radius:14px;display:block}.tab-nav{scrollbar-width:none;gap:8px;width:100%;padding:10px 24px 14px;display:flex;overflow-x:auto}.tab-nav::-webkit-scrollbar{display:none}.tab-btn{background:var(--bg);color:var(--text-muted);cursor:pointer;white-space:nowrap;box-shadow:var(--shadow-raised-small);border:none;border-radius:11px;flex-shrink:0;padding:9px 14px;font-size:13px;font-weight:500;transition:color .15s,box-shadow .15s,transform .15s;position:relative}.tab-btn:hover{color:var(--primary-dark);transform:translateY(-1px)}.tab-btn.active{color:var(--primary-dark);box-shadow:var(--shadow-inset);font-weight:700}.app-main{flex:1;width:100%;padding:36px 28px}.app-footer{width:100%;color:var(--text-muted);text-align:center;flex-wrap:wrap;justify-content:center;align-items:center;gap:4px 24px;padding:18px 24px;font-size:12px;display:flex;box-shadow:0 -5px 14px #a7aab53d}.progress-track{background:var(--border);height:3px}.progress-bar{background:var(--primary);transform-origin:0;border-radius:0 3px 3px 0;width:100%;height:100%;transition:transform .3s}.left-gap{margin-left:15px}@media (width<=800px){.playground-body{grid-template-columns:1fr}.playground-controls{border-right:none;border-bottom:1px solid var(--border)}.app-main{padding:20px 16px}.module-title{font-size:26px}.header-inner{padding:10px 16px}.course-mark{width:56px;height:56px}.app-footer{gap:4px;padding:16px}}@media (width<=420px){.tab-nav{padding-left:16px;padding-right:16px}}